Activated alumina

Activated alumina as a
desiccant, which works adsorption process. The moisture in the air will stick
to the alumina as the air passes through it. The water molecules become trapped
so that the air is dried out as it passes through the filter. This process of
regenerating the alumina is achieved when the activated alumina desiccant is
heated, it will let go of all of the water stored in it, allowing it to be used
over and over.